1. Field of the Invention
The present invention relates to a roller rail used in the field of dynamic layer storage for preparing orders or supplying workstations.
2. Discussion of Background Information
These roller rails are often composed of a profile made of sheet metal whose section is U-shaped or omega-shaped, open at the upper end and whose rims are arranged in order to accommodate the axles of the rollers, as described for example in U.S. Pat. No. 3,586,142.
Another type of rail, described in FR-A-2 563 506, comprises a sheet metal profiled rail and a plastic material strip which separates and maintains the rollers on the rail. This plastic strip also improves the resistance properties of the rail while preventing its opening to a certain extent when carrying heavy loads.
There are also rails using a U-shaped sheet metal profile, but open downwardly. The bottom of the U has been drilled to accommodate the rollers. This type of rail, described notably in U.S. Pat. No. 4,186,830, also comprises axles formed directly into the profile flanges. This type of rail is particularly economical and moreover it can be produced directly by profiling a sheet metal band, embossed in a previous stage.
However, this type of rail cannot contain a high density of rollers since a minimum quantity of matter must be preserved between the rollers so as not to make it brittle.
The present invention offers a rail structure similar to that described in the previously mentioned document FR-A-2 563 506. It advantageously offers still higher resistance and reduces the production cost significantly.